gpio: ml-ioh: Convert to use managed functions pcim* and devm_*

 When removing the module, we will get the following flaw:

[   14.204955] remove_proc_entry: removing non-empty directory 'irq/21', leaking at least 'gpio_ml_ioh'
[   14.205827] WARNING: CPU: 0 PID: 305 at fs/proc/generic.c:717 remove_proc_entry+0x389/0x3f0
...
[   14.220613]  ioh_gpio_remove+0xc5/0xe0 [gpio_ml_ioh]
[   14.221075]  pci_device_remove+0x92/0x240

Fix this by using managed functions, this makes the error handling more
simpler.

Fixes: e971ac9a ("gpio: ml-ioh: use resource management for irqs")
Signed-off-by: Zheyu Ma <zheyuma97@gmail.com>
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>